• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.47-47
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• 2011

최근 m-Aramid 섬유의 염색에 대한 연구가 진행되면서 기존의 원착법 및 초고온고압법 등 상업성이 낮거나 제약이 많았던 염색법에서 차츰 cationic dye를 이용한 염색법이 상용화되고 있다. m-Aramid 섬유는 amide기의 분자 간 수소결합으로 인하여 결정화도를 증가시킴으로서 고강도, 고탄성의 특성을 가질 수 있지만, 강력한 분자구조와 고결정성의 치밀구조로 인하여 염료가 섬유의 분자구조 내부로 확산, 염착되기 어려운 단점을 가지기도 한다. 따라서 m-Aramid 섬유를 침염법으로 염색 시, 섬유의 치밀구조를 이완시켜줄 수 있는 swelling agent가 중요하게 작용한다. 본 연구에서는 cationic dye를 이용하여 swelling agent의 영향성을 살펴보았다. 사용된 시료는 100% m-Aramid 섬유이며, C.I. Basic Yellow 28, Red 46, Blue 54를 사용하여, 욕비 1:10, $NaNO_3$ 7g/l의 조건으로 $130^{\circ}C{\times}60$분간 염색하였다. 이때 사용된 Swelling agent는 두 가지로 각각 1-phenoxypropan-2-ol(S1)과 N-methyl formanilide(S2)를 주성분으로 한다. 염색 시 염료의 농도는 0.5~7% o.w.f.이며, 염색 전 후 염욕을 UV-VIS을 통해 absorbance값을 측정하여 산출한 염착율과, CCM을 사용하여 최대흡수 파장에서 산출 된 K/S값을 비교 고찰 하였다. 각각의 염색물을 비교한 결과 Red 염료를 제외한 yellow 및 blue 모두 3% o.w.f. 염료농도까지 90% 이상의 흡착율을 보였으며, S1에 비해 S2의 경우 염착율이 근소하게 높은 결과를 보였다. 반면 K/S 값을 비교해보면, S2를 사용하였을 때 10%~60% 높은 K/S값을 보였다. 염착율은 비슷하지만 K/S값의 차이를 보이는 이유는 염색이 끝난 후 수세과정에서 섬유표면에 미고착된 염료들이 빠져나가는 것으로, 이를 통해 S2의 경우 섬유의 내부로 염료를 잘 고착시켜 줌으로서 수세안정성이 S1에 비에 우수한 결과를 보인 것으로 고찰된다.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.956-960
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• 1998

Cu-Zn and Cu-Zn-Ti catalysts for the steam reforming of methanol were prepared. This reaction was carried out at atmospheric pressure, $250^{\circ}C$, steam/methanol molar ratio 1.5, and contact time 0.1 g-cat.hr/mL-feed. In case of the catalyst with 3 mol% of $TiO_2$, the activity was superior to that of catalysts without $TiO_2$. The reaction products were mainly hydrogen and carbon dioxide. It was found that catalytic activity was not related to specific surface area but affected by metallic copper area which was measured by $N_2O$ decomposition and increased with the addition of $TiO_2$ content. XPS and XRD showed that the oxidation state of zinc was not changed during reaction, but oxidation states of copper existed in Cu(0) or Cu(I).

• Clinical and Experimental Reproductive Medicine
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• v.9 no.1_2
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• pp.43-53
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• 1982

여성의 난소기능은 뇨중 Oestrone-3-glucuronide를 간편한 solid-phase 의 화학발광성 면역학적 측정법 (Chemiluminescence Imrnunoassay(CIA) 에 의하여 그 기능이 탐지될 수 있다. Oestrone-3-g1ucuronyl-6-bovine serum albumine에 대한 antiserum의 IgG fraction은 polystyrene 실험관벽에 흡착시켰으며, 항원으로서는 est r one-3- gl ucuronyI-6-aminoethyl-ethyl-isoluminol 을 항원 (antigen) 에 labeI 시킨 것이다. 시험 대상물인 뇨는 매일아침뇨(early morning urine) 을 희석 (1:1000 V/V)한 후 100mcl 를 취하여 이를 각기 이중분석액으로 택하였다. 시험관 내에서 결합반응 (1 hour at $4^{\circ}C)이 일어난 후에는 시험관내의 액체를 전부 흡입 폐기시켰으며, 항체반응이 일어난 후 ( antibody-bound fraction )에는 완충액 (400mcl)으로 한번 세척시켰다. 그후 염화수산화물(2N , 200mcl)을 가지고 $22^{\circ}C$에 60 분간 방치 혼합케 한 후 효소(microperoxidase) 와 과산화수소를 가하면서 산화작용에서 발생되는 발광양을 10초동안 측정하여 그 결과를 분석하였다. 위에 기술한 분석방법을 평가하면 다음과 같은 결론을 얻었다. Calibration curve sensitivity$3.12{\pm}0.75$ PG/tube ($mean{\pm}SD$)였고, lntra-assay precision(CV%) 9.52 (20 replicates;$38.4{\pm}3.66$nmol/1) 와 8.81 (15 replicates; $102.4{\pm}8.82$nmol/1)였다. Inter-assay precision(CV%) 은 11.9 (mean of 4 pools-7.03, 23.16, 52.11 과 117.53 nmol/1)로 2개월 동안에 걸쳐 시행되었고, 평균 비이어스(mean bias)는 -0.78 로 28에서 448 nmol 범위로서 매일아침 "뇨"의 차이분(different aliquots)은 좋은 결과를 얻었다. 건강한 여성으로부터 채취된 뇨중 Oestrone-3-glucuronide 의 농도(nmol/1)를 보면 월경주기의 여포기와 배난기 및 황체기에 있어서 각기 $40.2{\pm}9.9$ , $102.3{\pm}39.4$와 $84.3{\pm}13.3$nmol/1였다. 이와같은 결과는 동일한 검사뇨를 방사면역학적 방법(RIA)으로 측정 (6 menstrual cycle)한 결과와 유사한 측정치를 얻으므로서 간편하고 진보된 좋은 방법중의 하나라고 사료되는바이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6575-6580
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• 2013

Various modified SCR catalysts were prepared and tested to improve the strength of catalysts for use under severe conditions. The SCR catalysts were modified with a binder and dispersion agent, and tested at the fixed bed reactor. FT-IR and $H_2$-TPR were used to analyze the degree of hydrogen use and ammonia adsorption by the modified catalysts. In the case of the SCR catalysts coated with 2.3g of the binder, 4.7g of ethanol, and 0.1g of dispersion agent, the strength of catalyst was increased by approximately 12%. On the other hand, despite the enhancement of strength, the activities of the SCR catalysts were decreased by 2-10%. When the mixed solution composed of binder, dispersion agent and $SiO_2$ solution was precipitated on the catalyst, the $NO_x$ conversion of the catalyst was decreased slightly. The Bronsted acid site and Lewis acid site worked as the activators for the SCR reaction, and were decreased by $SiO_2$.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.254-258
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• 2006

Zeolites with excellent adsorption capacity of volatile organic compounds were attached onto inorganic fibers which were the raw materials of honeycomb-type adsorbers. The amounts of zeolite particles attached onto the fibers considerably increased by treating them with hydrochloric acid, sulfuric acid, or hydrofluoric acid. Various functional groups such as chloropropyl, aminopropyl and epoxy groups of silane compounds, and amine groups of polyethylenimine were employed as covalent linkage materials between the fibers and zeolite particles. The state of the fibers coated with zeolite particles was examined by scanning electron microscopy, and the amounts of zeolite particles bound to the fibers were estimated from their BET surface areas. The largest amount was obtained when polyethylenimine was employed as a linkage material. Polyethylenimine was the most effective for attaching zeolite particles onto the inorganic fibers among various linkers employed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.2
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• pp.276-283
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• 1997

A dry impregnation method was used for preparing pellet type Pt/$SnO_2$ gas sensor. The crystal structure, direction of the crystal, crystal size and microstructure between the catalyst and the support ($SnO_2$) were characterized with electron diffraction analysis, transmission electron microscopy, scanning electron microscopy. The characterization indicates that when Pt/$SnO_2$ sample is calcined at $400^{\circ}C$, the Cl content associated with the Pt phase diminishes and the part of Pt is moved into $SnO_2$ support. This results in the enhancement of gas sensitivity. After the reactor with a Pt/$SnO_2$ sample was run with a flow rate of 30 sccm (a mixture of 0.5% $H_2$ in $_N2$) for a while, the resistance of $SnO_2$ was saturated, but the $SnO_2$ kept absorbing $H_2$ gas. This indicates that the surface state was saturated. For the 14 ppm $H_2$ gas, the sensitivity of Pt/$SnO_2$ devices was about 81% at an operating temperature of $300^{\circ}C$.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.24-34
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• 1992

Recent studies dealing with the fundamental understanding and applications of bimetallic catalysts are discussed. Bimetallic catalysts have had a major industrial impact, specifically for the reforming of petroleum naphtha, for the hydrogen reduction of carbon monoxide, and for the three way catalytic converter system. The action of the bimetallic catalysts in these reactions may be interpreted in terms of ensembles, electronic influences and surface structure. Various combinations of metal pairs have been considered in order to evaluate the role played by the added metals. For catalyst selectivity control, the possibility of surface enrichment of one element has been recognised. More generally, the influence of preparative variables on the formation of supported catalysts has been clarified, In particular by temperature programmed reduction (TPR). Information on the structure of bimetallic catalysts has been obtained with chemical probes, such as chemisorption and reaction rate measurement and physical probes, such as extended X-ray absorption fine structure (EXAFS), scanning transmission electron microscopy (STEM) and Xe-NMR.

• Membrane Journal
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• v.24 no.3
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• pp.177-184
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• 2014

Silica membranes with high permeability were prepared using colloidal and polymeric silica sols on a porous stainless steel-tube support by a DRFF and SRFF method. Silica sols were derived with tetraethylorthosilicate (TEOS) by sol-gel method and analyzed with DLS, FE-SEM, and $N_2$ adsorption. The coating of the intermediate layer with colloidal silica sol on the stainless steel-tube support led to a denser surface morphology of the membrane along with a considerable reduction in the number of surface defect. As the polymeric silica sol enclosed the colloidal silica sol with spherical particles during the SRFF method, the separation-layer-coated silica membrane showed a denser surface than the intermediate layer. Moreover, the silica membranes showed high hydrogen gas permeability of $(6.63-9.21){\times}10^{-5}mol{\cdot}m^{-2}{\cdot}s^{-1}{\cdot}Pa^{-1}$ with low $H_2/N_2$ perm-selectivity (2.9-3.1) at room temperatures.

• Journal of the Korean Applied Science and Technology
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• v.20 no.1
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• pp.72-79
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• 2003

The impregnated activated carbons were prepared by the incipient wetness method with the contents of $KIO_3$ varied from 1.0${\sim}$10 wt% as the impregnation material. The specific surface area and micropore volume of the rice hulls activated carbon were $2,600{\sim}2,800$ $m^2$/g and 1.1${\sim}$1.4 cc/g, respectively. With increasing the contents of impregnation materials, the surface area and micropore volume decreased by 3${\sim}$21%. However, The amounts of hydrogen sulfide adsorbed increased by 2.1${\sim}$2.8 times depending on the impregnation content. The optimum contents of $KIO_3$ were 2.4 wt%. Although the breakthrough time and adsorption capacity of hydrogen sulfide decreased with increasing temperature in the case of the unimpregnated activated carbons, they increased by 1.2${\sim}$ 3.2 times for the case of the impregnated activated carbons. The optimum aspect ratio(L/D) was 1.0 and the adsorption amount of hydrogen sulfide enhanced with increasing the gas flow rate. The regeneration temperature was determined as 400$^{\circ}C$ from the TGA experiment. The adsorption capacity of hydrogen sulfide with the impregnated activated carbon decreased gradually as the regeneration continued. The hydrogen sulfide adsorption amount of the regenerated activated carbon up to 4 times was still higher than that of the unimpregnated activated carbon.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.594-598
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• 2012

Polymer electrolyte membrane fuel cell(PEMFC) performance degrades seriously when sulfur dioxide and hydrogen sulfide are contaminated in the fuel gas at anode and air source at cathode, respectively. This paper reveals the effect of the combined sulfur impurity poisoning on both PEMFC cathode and anode parts through measuring electrical performance on single FC operated under 1 ppm to 10 ppm impurity gases. The severity of $SO_2$ and $H_2S$ poisoning depended on concentrations of impurity gases under optimum operating conditions($65^{\circ}C$ of cell temperature and 100 % relative humidity). Sulfur adsorption occured on the surface of Pt catalyst layer on MEA. In addition, MEA poisoning by impurity gases were cumulative. After four consecutive poisonings with 1, 3, 5 to 10 ppm, the fuel cell performance of PEMFC was decrease upto 0.54 V(76 %) from 0.71 V.